The exemplary embodiments described herein relate generally to wireless telecommunications. In particular, various embodiments are directed to techniques for improving power control at base stations that employ multi-core processors. While the exemplary embodiments are particularly directed to the art of wireless telecommunications, and will be thus described with specific reference thereto, it will be appreciated that the exemplary embodiments may have usefulness in other fields and applications.
By way of background, LTE (Long Term Evolution) is a rapidly evolving 3GPP project that aims to improve the UMTS (Universal Mobile Telecommunications System) mobile phone standard to cope with future communication network demands. LTE improves wireless network efficiency and bandwidth, lowers costs, and enhances the service experience. Specifically, LTE makes use of new spectrum opportunities and offers better integration with other open standards. LTE generally includes an LTE RAN (Radio Access Network) (also known as E-UTRAN) along with an EPS (Evolved Packet System, also called Evolved Packet Core).
Communication systems are generally split into two primary functions: data plane functions and control plane functions. In previous LTE products, at least two processors were used on the modem board: one processor to support the control plane functions (non-real time, e.g., Operations, Administration, and Management (or OA&M), call management processing-related functionalities, and transport processing), and another processor to terminate and support the data plane functions (real time, e.g., LTE Layer 2 processing). Both the control and data planes used different operating system (OS) instances, such as Linux for the control plane and a real-time OS such as vXWorks (made and sold by Wind River Systems of Alameda, Calif.) for the data plane core. Typically, one modem board supported one sector or cell. So to support multi-cell (e.g., three cells or six cells) configurations in such a system, it would be necessary to provide as many modem boards as the number of cells.
As an improvement, a multi-core processor may be used in an LTE wireless base station (e.g., on a modem board). A base station typically requires multiple sectors or cells to provide suitable coverage, but it is possible for a single modem board to support these multiple sectors or cells if a multi-core processor is deployed on the modem board. In that case, an operating system, such as SMP Linux with PREEMPT RT patch, runs on one SMP (symmetric multiprocessing) partition that contains all eight cores. In this configuration the control plane (i.e., non-real time threads and processes) and the data plane (i.e., real time threads and processes) share the same operating system instances even though they are bound to run on different cores.
While these multi-core processors and System on Chip (SOC) devices are extremely powerful, they do consume a lot of power. For example, the FSL P4080 8 core processor consumes approximately 27 watts when the cores are running at 1500 MHz. Currently, however, there is no dynamic power control in the base station to reduce the multi-core processor power consumption. Thus, there is a need to reduce the power consumption based on system usage, for example. This would result in cost savings for the service provider and a greener base station that is better for the environment.